Abstract: A High Temperature Superconductor, HTS, magnet comprising a coil formed of nested concentric windings. Each winding comprises HTS material. The HTS magnet further comprises a conductor element comprising an electrical contact surface through which to supply electric current to a portion of at least one of the windings. The surface provides electrical contact between the conductor element and an axial edge of the coil substantially around the path of the at least one of the windings.

Abstract: A high temperature superconducting, HTS, field coil. The HTS field coil comprises a plurality of turns comprising HTS material and metallic stabilizer; and a partially insulating layer separating the turns, such that current can be shared between turns via the partially insulating layer. The partially insulating layer comprises an insulating region, and a plurality of electrically conductive paths through the insulating region, wherein current can be shared between the turns via the electrically conductive paths. Each electrically conductive path comprises an HTS bridge comprising HTS material, wherein the HTS bridge is in series with normally conducting material of the electrically conductive path.

Abstract: A High Temperature Superconductor, HTS, magnet comprising a coil formed of nested concentric windings. Each winding comprises HTS material. The HTS magnet further comprises a conductor element comprising an electrical contact surface through which to supply electric current to a portion of at least one of the windings. The surface provides electrical contact between the conductor element and an axial edge of the coil substantially around the path of the at least one of the windings.

Abstract: A high temperature superconducting, HTS, magnet system. The HTS magnet system comprises an HTS field coil, a temperature control system, a power supply, and a controller. The HTS field coil comprises a plurality of turns comprising HTS material; and a resistive material electrically connecting the turns, such that current can be shared radially between turns via the resistive material. The temperature control system is configured to control the temperature of the coil, the temperature control system comprising at least a cryogenic cool system configured to keep the coil below a self-field critical temperature of the HTS material. The power supply is configured to supply current to the HTS field coil. The controller is configured to cause the power supply to provide a current greater than a critical current of all of the HTS material.

Abstract: A method of joining a first substrate and a second substrate to thereby form a joint. A stack is provided, including filler material and a plurality of retention mediums, between the first and second substrate. The stack is heated to melt the filler material and to wet the first and second substrate with melted filler material. Said melted filler material is allowed to solidify to form the joint.

Abstract: According to a first aspect, there is provide an HTS current lead. The HTS current lead comprises an HTS cable comprising a plurality of HTS tapes; a braided sleeve around the HTS cable; and a stabiliser material impregnating the HTS cable and the braided sleeve. The stabiliser material has a melting point above a critical temperature of the HTS tapes and below a thermal degradation temperature of the HTS tapes.

Abstract: A high temperature superconducting, HTS, tape. The HTS tape comprises a superconducting layer a superconducting layer formed from HTS material, a substrate, and one or more buffer layers separating the superconducting layer from the substrate. The HTS tape further comprises a plurality of holes extending at least through the superconducting layer and the one or more buffer layers and conductive material within each hole. The conductive material provides an electrical connection to the superconducting layer through the one or more buffer layers via the hole.

Abstract: A cable for carrying electrical current in a coil of a magnet. The cable comprises a stack of tape assemblies. Each tape assembly has a length and a width, such that the length is much larger than the width, and each tape assembly comprises an HTS layer of anisotropic high temperature superconductor. HTS material, wherein a c-axis of the HTS layer is at a non-zero angle to a vector perpendicular to the plane of the HTS layer. The tape assemblies are stacked as a series of pairs, each pair comprising first and second HTS tape assemblies and a copper layer therebetween. The tape assemblies in each pair are arranged such that the c-axis of the HTS layer of the first HTS tape assembly of each pair have reflective symmetry to the c-axis of the HTS layer of the second HTS tape assembly of each pair about a plane which is parallel to and equidistant from each HTS layer.

Abstract: A High Temperature Superconductor, HTS, magnet comprising a coil formed of nested concentric windings. Each winding comprises HTS material. The HTS magnet further comprises a conductor element comprising an electrical contact surface through which to supply electric current to a portion of at least one of the windings. The surface provides electrical contact between the conductor element and an axial edge of the coil substantially around the path of the at least one of the windings.

Abstract: A method of energizing or de-energizing a high temperature superconducting, HTS, coil, from an initial transport current to a final transport current. The HTS coil comprises a plurality of turns of HTS material. A transport current is supplied to the HTS coil, the transport current starting at the initial transport current and varying over time to the final transport current. Cooling is applied to the HTS coil. An operating condition of the HTS coil is monitored, wherein the operating condition is indicative of a ratio I/Ic of the transport current, I, to a critical current, Ic, of the HTS material in at least a part of the HTS coil. One or both of the transport current applied to the coil and a net cooling applied to the coil are controlled in a feedback loop responsive to the operating condition, in order to maintain the operating condition in a desired range during energisation or de-energisation, such that the indicated ratio I/Ic is maintained above a threshold ratio (e.g. 0.7).

Abstract: A High Temperature Superconductor, HTS, magnet comprising a coil formed of nested concentric windings. Each winding comprises HTS material. The HTS magnet further comprises a conductor element comprising an electrical contact surface through which to supply electric current to a portion of at least one of the windings. The surface provides electrical contact between the conductor element and an axial edge of the coil substantially around the path of the at least one of the windings.

Abstract: A high temperature superconducting, HTS, current lead comprising an HTS cable including a plurality of HTS tapes, a braided sleeve around the HTS cable, and a stabiliser material impregnating the HTS cable and the braided sleeve, the stabiliser material having a melting point above 290K and below a thermal degradation temperature of the HTS tapes.

Abstract: A method of manufacturing a High Temperature Superconductor, HTS, field coil from one or more HTS tapes. Each HTS tape comprises an HTS material layer. The method comprises: winding the one or more HTS tapes about an axis to form a field coil comprising windings of HTS tape; and removing material from an axial edge of the one or more of the HTS tapes around at least a part of one or more of the windings to reduce the extent of the one or more HTS tapes along the axis of the field coil.

Abstract: A high temperature superconducting, HTS, field coil. The HTS field coil comprises a plurality of turns comprising HTS material and metallic stabilizer; and a partially insulating layer separating the turns, such that current can be shared between turns via the partially insulating layer. The partially insulating layer comprises an insulating region, and a plurality of electrically conductive paths through the insulating region, wherein current can be shared between the turns via the electrically conductive paths. Each electrically conductive path comprises an HTS bridge comprising HTS material, wherein the HTS bridge is in series with normally conducting material of the electrically conductive path.

Abstract: A high temperature superconducting, HTS, magnet system. The HTS magnet system comprises an HTS field coil, a temperature control system, a power supply, and a controller. The HTS field coil comprises a plurality of turns comprising HTS material; and a resistive material electrically connecting the turns, such that current can be shared radially between turns via the resistive material. The temperature control system is configured to control the temperature of the coil, the temperature control system comprising at least a cryogenic cool system configured to keep the coil below a self-field critical temperature of the HTS material. The power supply is configured to supply current to the HTS field coil. The controller is configured to cause the power supply to provide a current greater than a critical current of all of the HTS material.

Abstract: According to a first aspect, there is provide an HTS current lead. The HTS current lead comprises an HTS cable comprising a plurality of HTS tapes; a braided sleeve around the HTS cable; and a stabiliser material impregnating the HTS cable and the braided sleeve. The stabiliser material has a melting point above a critical temperature of the HTS tapes and below a thermal degradation temperature of the HTS tapes.

Abstract: A High Temperature Superconductor, HTS, magnet comprising a coil formed of nested concentric windings. Each winding comprises HTS material. The HTS magnet further comprises a conductor element comprising an electrical contact surface through which to supply electric current to a portion of at least one of the windings. The surface provides electrical contact between the conductor element and an axial edge of the coil substantially around the path of the at least one of the windings.

Abstract: A high temperature superconducting, HTS, field coil. The HTS field coil has a plurality of turns and a semiconductor, arranged such that current can be shared between the turns via the semiconductor.

Abstract: A cable for carrying electrical current in a coil of a magnet. The cable comprises a stack of tape assemblies. Each tape assembly has a length and a width, such that the length is much larger than the width, and each tape assembly comprises an HTS layer of anisotropic high temperature superconductor, HTS material, wherein a c-axis of the HTS layer is at a non-zero angle to a vector perpendicular to the plane of the HTS layer. The tape assemblies are stacked as a series of pairs, each pair comprising first and second HTS tape assemblies and a copper layer therebetween. The tape assemblies in each pair are arranged such that the c-axis of the HTS layer of the first HTS tape assembly of each pair have reflective symmetry to the c-axis of the HTS layer of the second HTS tape assembly of each pair about a plane which is parallel to and equidistant from each HTS layer.

Abstract: A monitoring device for use in a cryogenic system. The monitoring device comprises first and second conducting elements and a current detector. The first conducting element comprises high temperature superconducting, HTS, material and is configured for connection to a current source and insertion into the cryogenic system. The second conducting element comprises HTS material and is connected in parallel to the first conducting element by first and second joints. The current detector is configured to detect a current in the second conducting element. When the HTS material in each of the first and second conducting elements is in a superconducting state, the resistance, RT, of the first conducting element between the first and second joints, is less than the sum, RB, of the resistance of the second conducting element between the first and second joints and the resistances of the first and second joints.